Area under the graph comparing real world performance of engines

[sars]

It seems that there is little discussion on the actual topic, which was the area under the graph and real world performance. Whilst there is a definite advantage to having more torque, the obvious advantage of forced induction, it is not though the be end and end all of driveability and performance, if that were the case we would all love diesels. Having more torque at the crank does not alone give great acceleration, it has to be combined with the correct gearing. So the 3.0 straight six will have slightly different gearing setup to that of the turbo four pot, this caters for lower torque but a higher useable rpm range. The actual graphs you should be comparing is the torque at the driven wheels in each gear.

As for which is better, two points, BMW is famous for it's three litre straight six and second that famous saying "there is no substitute for cubic inches "

 

[Anonymous]

Not wishing to muddy the waters even more so but .....
The G29 has a 4cyl version in the M30i (if that's the correct nomenclature) what capacity is that engine and what are the output figures?

The G29 20i 30i use the successor to the N20 ie 2 litre 4 cylinder turbo with some incremental twiddles,,the N20 was the watershed point..the B48 is an iteration, slightly longer stroke for even more low down torque..slight change in balance shaft configuration to make it even smoother than a six..

It’s also a closed deck design capable of taking more boost / compression /power than the N20 subject to adequate cooling..

 

[Anonymous]

It seems that there is little discussion on the actual topic, which was the area under the graph and real world performance. Whilst there is a definite advantage to having more torque, the obvious advantage of forced induction, it is not though the be end and end all of driveability and performance, if that were the case we would all love diesels. Having more torque at the crank does not alone give great acceleration, it has to be combined with the correct gearing. So the 3.0 straight six will have slightly different gearing setup to that of the turbo four pot, this caters for lower torque but a higher useable rpm range. The actual graphs you should be comparing is the torque at the driven wheels in each gear.

As for which is better, two points, BMW is famous for it's three litre straight six and second that famous saying "there is no substitute for cubic inches "

The gearing point is advantage N20...the 8 speed auto outclasses (apart from emotion ) the 6 speed manual / 6 speed auto in all aspects..

The 6 speed manual N20 is on a par with 6 speed manual 30i ..

The re-mapped N20 therefore outshades the 30i under any circumstances..the difference widens with the N20 8AT vs either the N52 6AT which is slightly worse than the N52MT

 

[sars]

The gearing point is advantage N20...the 8 speed auto outclasses (apart from emotion )

and that is where, in my humble opinion, you lost the argument. Driving is all about the emotion

 

[Smartbear]

The gearing point is advantage N20...the 8 speed auto outclasses (apart from emotion )

and that is where, in my humble opinion, you lost the argument. Driving is all about the emotion

But you’ve got diseasels in your sig Sars, where’s the emotion there?
Rob

 

[Boltz]

It's been 10 years since I drove a 6 cylinder E89 but I wouldn't mind driving two equally specced i4 and i6 cars back to back. Not to gauge the straight line performance, but to see if there really is that much difference in the handling stakes from the weight saving over the front axle

MACK, this is what I did last week drove my upgraded 18i N20 then jumped straight into a 2011 six pot with both being manual cars. When finished I then drove my car on the same route I had drove in six pot. But for me the six pot felt too heavy in the bends and although the sound gave me an erection the handling put me back into limp mode. So if anyone is in the West Mids and wants to experience an upgraded N20 give me a shout and it will be my pleasure to meet you and take you out in my car.

 

[MACK]

Oh no MACK - you’ve now introduced Auto v Manual into this perennial conundrum!

I know, I did think twice before I wrote that!

 

[MACK]

It's been 10 years since I drove a 6 cylinder E89 but I wouldn't mind driving two equally specced i4 and i6 cars back to back. Not to gauge the straight line performance, but to see if there really is that much difference in the handling stakes from the weight saving over the front axle

MACK, this is what I did last week drove my upgraded 18i N20 then jumped straight into a 2011 six pot with both being manual cars. When finished I then drove my car on the same route I had drove in six pot. But for me the six pot felt too heavy in the bends and although the sound gave me an erection the handling put me back into limp mode. So if anyone is in the West Mids and wants to experience an upgraded N20 give me a shout and it will be my pleasure to meet you and take you out in my car.

Thanks for the feedback, interesting account were both cars M Sport spec? I remember from messing around with the suspension on my E85 the difference between SE, M Sport and Eibach springs was quite considerable.

 

[Boltz]

Both Msport cars

 

[MACK]

Both Msport cars

Thanks might have to try one for myself

 

[Boltz]

Thanks might have to try one for myself

MACK, definitely worth doing, the six pot I drove is currently up for sale at my local BMW stealers.

 

[tomscott]

My clubman jcw has the B48 which is the newer version of the N20 and it’s a cracking engine loads of character and great power curve even in frame of the Clubman although they aren’t that heavy being 1220kg.

It’s not very economical with about 42 max on the motorway about 30mpg combined over 25k.

Really like it as a daily and it’s probably because of the engine. Plus it’s such an easy drive.

231hp 320lbs 0-62 6.1

Having this makes having the Z4M as a weekender feel quite special and it’s like a work out in comparison but in real world use how much quicker it actually is... probably not much.

I get the N20 in a Z4 as a daily, as a weekender and after a test drive in a 35i that would be my direction but decided the E85 Z4M was a better car and bought another one.

I would also disagree that noise is not important the noise is half the experience.

 

[Maria1]

The point that this thread raises is that we all alighted on an E89 as a nice car to have but we all differ as to why we chose it. I would argue that we must all like how it looks - that has to be our common-denominator. But we all then have different parameters which resulted on a different specification chosen. This might be cost, handling, engine, practicality, performance, mpg, etc.

I chose it for the good value it represented as a lightly used secondhand car, style and the engine. But not for performance. A sport/GT car has to go reasonably well, clearly, but 250bhp - even in today's high-bhp world - is still ample even with a low torque NA engine. I respect that the 20i/28i probably goes better and has better mpg but does it stir the soul? Nah. Not at all. No straight four cylindered engine does and I had a LCC Rocket with a Yamaha EXUP mill at the back revving out to 11500rpm. Great engine, yes. Race-derived Rusell Savory motor, yes. Lots of noise, yes. Go like a hell, naturally. Sound good, no. It was like having a bag of spanners being shaken violently three inches behind my head. Sound and feel is really important to me. But, not so much to others; they look at other parameters.

So, I use our 30i Auto to trundle about, using it in Drive most of the time, mashing my foot on the pedal if I want to get past things and that suffices. After I get out of it I look back at it and think "Yes, good looking car." However, I never think "That was the drive of my life." That is because the Z4 doesn't really engage in the handling stakes. Yes, it was fabulous at doing 1000 miles in one hit (from Spain to Brittany) in March to escape Covid-19 and I really REALLY admired it for that but not as a real driver's machine. I have to say that my vintage Honda NSX is light years ahead in poise, responsiveness, lightness, feel and comfort. In contrast, the E89 feels like a tank (although I do accept that the high long bonnet accentuates this - the NSX has nothing other than two wheel arches low down on the A pillar).

As such, I am still surprised that people buy a Z4 and then try to make it handle. I would not have bought a Z4 if I wanted a car that handled - this is in respect of some posters here who are saying that the lighter 20i is better than the 30i. Well, as indicated above my view is that both are pants "out of the box" even if the 20i is better. Road roller suspension and crashing over UK's dreadful pot-holed roads even on non-RFTs. Simply, E89s are outclassed in the handling and ride stakes by others irrespective of the engine chosen.

But that is just my view. I accept that I am lucky enough to have experienced other cars that might be better than the E89 and some may never have that. However, despite these shortfalls, I still chose a E89 as a car to use as a summer car because it's still a nice car. AND THAT IS IRRESPECTIVE OF THE ENGINE CHOSEN.

 

[MACK]

Well we are veering off topic again. In an attempt to steer us back to the point of the thread I think it's worth highlighting one aspect that's not really got a mention.
Value, on a like for like basis an a equivalent N20 is a fair chunk cheaper than a 30i. Not to mention cheaper to run too, with much better fuel economy and low tax etc. These will be big factors for a lot of people. On the face of it buying a 30i is a much more costly proposition to gain a bit of engine noise. Granted an 30i does sound good, but it's certainly not up there with the best sounding engine's out there. So although it will be a must for some, I imagine for most the N20's performance/value/efficiency advantages would win out. Factors I'm sure weren't lost on the BMW engineers and bean counters etc.

 

[Maria1]

Hijack acknowledged. I have started a new thread on "Why did you chose your E89?" - sorry if it's been done before. On a related point to the N20/N52, and while bean counters will always have an interest, the 4 pot turbo came about largely because of emissions. Turbos now are everywhere (apart from Mazda but they have always been oddball) and will be the new default taking over from diesels - at least until EV takes over. Enjoy your petrol engine while you can.

 

[Boltz]

Spot on MACK My 18i Msport was a hell of a lot cheaper than a 28i or a 3.0 and even with the upgrades I have still saved a considerable amount of money and what topped it off for me this morning was reversing out of my mates garage and two lads who were there with an S3 commented on how nice my car sounded with the Supersprint system fitted!!

 

[Silverstar]

Value, on a like for like basis an a equivalent N20 is a fair chunk cheaper than a 30i. Not to mention cheaper to run too, with much better fuel economy and low tax etc.

Off topic I know but ask yourself why the N20 is much cheaper than the 30i and why values for it are holding firm against the newer models and I suspect will continue to do so. As for running cost sure you might save a few quid on tax but fuel economy whilst the N20 shows a marked improvement on paper I doubt in the real world there is that much of a difference that for most people the cost saving unless you are doing mega miles a year would make much of any difference.

 

[sars]

The gearing point is advantage N20...the 8 speed auto outclasses (apart from emotion )

and that is where, in my humble opinion, you lost the argument. Driving is all about the emotion

But you’ve got diseasels in your sig Sars, where’s the emotion there?
Rob

It’s called learning by ones past experiences, hence the biturbo 3.0l V6

 

[MACK]

Value, on a like for like basis an a equivalent N20 is a fair chunk cheaper than a 30i. Not to mention cheaper to run too, with much better fuel economy and low tax etc.

Off topic I know but ask yourself why the N20 is much cheaper than the 30i and why values for it are holding firm against the newer models and I suspect will continue to do so. As for running cost sure you might save a few quid on tax but fuel economy whilst the N20 shows a marked improvement on paper I doubt in the real world there is that much of a difference that for most people the cost saving unless you are doing mega miles a year would make much of any difference.

I did ask myself this question before buying and the conclusion I drew was simple. It's down to manufacturer product market positioning that feeds down into the secondhand market. When most people are talking about an E89 N20, they're actually talking about the 20i model which makes up the majority. However that model was a direct replacement for the 23i not the 30i. The 28i replaced the 30i and its prices (broadly speaking) takeover where the 30i leave off, which is what you would expect for a replacement model. Again broadly speaking 23i prices are far cheaper than the 30i, which reflects its market position and performance deficit over its stablemate. But I bet a fair chunk of buyers would opt for a 23i instead of a 30i if they knew for circa £300 upwards of remap it was possible to increase the grunt to far in excess of 30i. Obviously in the real world you can't do this with i6 as the engines in the 23/30i are physically different. But you can with the 18/20/28i as they use the same engine. The 28i also sound better than a 18/20i from the factory, which is solely down to their mapping (they use the same intake/exhaust etc)and again a remap gives you this nicer throatier note and then some. The only physical difference between a 20i and a 28i is the front brakes are bigger, which is quick and cheap to remedy if required.

 

[enuff_zed]

As for running cost sure you might save a few quid on tax but fuel economy whilst the N20 shows a marked improvement on paper I doubt in the real world there is that much of a difference that for most people the cost saving unless you are doing mega miles a year would make much of any difference.

Well I have to say that I didn't even consider fuel economy when I bought mine, a it's a weekend toy. However on quite a few occasions I have seen it displaying an average consumption of 41mpg, which pears to be exactly what the book says? First time I've had any car that did that.
Playing around the country roads over this neck of the woods it is sticking firmly at 36.6mpg.
Gave it a good old blast on the 80 odd mile detour I did coming home from the remap (sorry, that word again), got home, checked the consumption...................still 36.6mpg.
But I'm not making a cost saving at all, as it is an extra car I don't really need, and I have no other weekend cars to compare it to.